Age- and sex-specific bone mineral measures have not been available for healthy preschool children. We determined bone mineral content (BMC) and bone width in 89 children 1 to 6 years of age using direct photon absorptiometry at the one-third distal radius site. The BMC increased significantly with age, and bone width increased slightly with age. After stratification by age, male and female children had similar BMC from 1 to 4 years of age, but female children had significantly lower BMC at 5 to 6 years of age.